Method for sorting out certain containers, such as industrial containers, bottle crates etc. from a stock of containers and a device on a container for the identification of a to be sorted out container

ABSTRACT

Containers, e.g. bottle crates, industrial containers, of a common issue (Fxx1), e.g. a manufacturing series, are provided with a specific marking which indicates that they belong together. The mixing up of the various issues (Fxx1 . . . Fyz1 . . . Fzz2) which occurs during the circulation (Z, RZ) can again be reversed in an automatic sorting process, which makes it possible to sort out a desired sub-quantity (Fxx1) and to subject same to a further process stage (Rxx1, Axx1). The marked containers display an optically readable marking (3, 4), from which the information for the automatic sorting out of an issue can be noted.

The invention lies in the field of the transport of piece goods andrelates to a method for sorting out certain containers, such asindustrial containers, bottle crates etc., from a stock of containersand to a device on a container for the identification of a to be sortedout container whereby containers from a stock of containers are sortedout by means of optical detection characterized in that the containersof a common issue are provided with a specific marking from which it canbe noted that they belong together, in that after being mixed up duringuse the containers of a common issue are again brought together and inthat the sorted quantity of a common issue is eliminated from theoverall quantity.

Bottle crates as containers for a certain number of bottles, belong tothe type of re-usable containers, the circulation factor of which, ie.the number of re-utilizations, may assume quite high values. At anaverage circulation time of 5 days and an average service life of aplastic bottle crate of 8 years, an average circulation factor of closeon 600 can be expected. This relates in an idealised manner to one itemand its service life, during which these circulations naturally do nottake place in a uniform manner, ie. seen on a time axis shorter andlonger cycles are the cause of an inhomogeneous distribution. If, forexample, a total of 1000 crates is brought into circulation at the sametime, the initially sequenced quantity very quickly comes out ofsequence, so that already in the first third of the average life of acrate one can expect a broad distribution of the individual circulationfactors in accordance with the laws on statistics.

An additional problem is created by the requirement that a container,eg. a bottle crate, should not be used after it is damaged and also notafter it presents a shabby appearance. Such bottle crates must beremoved from circulation in good time. Furthermore, one must still takeinto account the remarkably high number of bottle crates of a stock ofbottle crates, which may easily run into millions. Together with thedropping out of sequence within individual issues of new bottle cratesduring the circulation and the dropping out of sequence of the variousissues amongst one another, there would result in time an intimatelymixed stock of recent bottle crates which, however, due to manycirculations have aged quickly, and old bottle crates which because of agentle treatment have remained intact. There also often occur defectiveseries of any type and quantity. Thus, in the case of bottle crates forexample, it is important that one is able to eliminate certain defectiveseries, the defectiveness relating mainly to a lack of mechanicalstability, seeing that this type of transport containers may be stackedvery high and such defective items may cause such a stacking system tocollapse. However, to keep such an overall stock to a certain degree ina usable condition by a sorting out of battered, defective andunsatisfactory bottle crates, requires a lot of work and is quitecostly.

Nevertheless, more and more breweries, for example, intend to sort outtheir stock of bottle crates and to eliminate aged bottle crates. Thisalso applies, however, to other branches where the stock of containersreaches considerable numbers.

It is the aim of the invention to indicate a method by which the sortingout of aged and/or defective containers, as well as of containers whichat an early stage are recognised as having been made defectively, eg.industrial containers, bottle crates, etc., from a stock of containersof any size, ie. from any quantity, can take place in the shortestpossible time and in an economical manner.

It is furthermore the aim of the invention to create, with a view tosuch large numbers of items, an as economical as possible device bywhich the method for the sorting out can be performed.

Furthermore it is the aim of the invention to design the device in sucha manner that the conventional and to some extent already existing meansfor the sorting out can be used.

The aim is achieved by the invention whereby containers of a commonissue are provided with a specific marking from which it can be notedthat they belong together, in that after being mixed up during use thecontainers of a common issue are again brought together, and in that thesorted quantity of a common issue is eliminated from the overallquantity.

The invention will now be discussed in detail with the aid of thefollowing figures, using the example of a stock of bottle crates used bythe wholesale producers of drinks. Shown are:

FIG. 1 a diagrammatic representation of the method according to theinvention;

FIG. 2 a first embodiment of the device according to the invention on abottle crate;

FIG. 3 a second preferred embodiment of the device on a container, whichmay be a bottle crate or an industrial container, and

FIG. 4 a code arrangement of the embodiment according to FIG. 3.

In principle there exist two possibilities for sorting out defective,damaged, too old or shabby looking bottle crates: the systematic sortingout, with which after going through the entire stock practically all theto be eliminated items are removed, or also the sporadic sorting outwith which the items, which by a natural random process arrive at anexisting check point or check points, are removed from the overallstock.

The systematic method undoubtedly entails costs which in the case ofsmaller quantities to be checked increase linearly with the size of thequantity, and in the case of larger quantities in a proportion which isno longer linear to the size of the quantity. The stock of bottle cratesof an average brewery will be of a magnitude at which the costs for thesorting out increase superproportionally.

With the sporadic sorting out, the quality of the sorting out depends onhow long it takes before the entire stock has passed the check point orcheck points once. In the case of very large quantities, ie. severalhundreds of thousands of bottle crates, such a cycle may exceed theaverage service life of a bottle crate, ie. there occur more bottlecrates that should be eliminated than are eliminated, as a result ofwhich the overall stock becomes, of course, successively older andolder. However, if in order to also remedy this a larger number of checkpoints are provided so as to increase the throughflow, or in order toreduce the time of the checking cycle in such a way that it lies wellbelow the average service life of a bottle crate, this soon results inan unprofitable amount of work, in which connection it should then beconsidered whether at practically the same amount of work one should notprefer a systematic checking as described above.

The systematic checking undoubtedly provides better results, but isalways expensive and, a point which should not be overlooked if theresult is not to be endangered, a predetermined minimum amount of workis unavoidable. In other words, in contrast to the abovethroughflow-and-random method, the sorting effort cannot be varied atwill; below a certain minimum amount of work, which depends on thequantity to be checked, the result collapses.

The method according to the invention aims at assisting the systematicsorting out and at minimising the work required for this, which shoulddirectly result in a greater economy. The device according to theinvention makes it possible to perform the method within and with theexisting means. If the firms in question did not until now ensure acontinuous renewal of their stock of bottle crates, this is due to thefact that as yet no method was known which is efficient and at the sametime also profitable.

It is a characteristic of the method to provide a specific marking onthe individual issues of the bottle crates in such a manner that bymeans of an optical mechanical process bottle crates of the same issuecan automatically be combined into a sub-quantity and separated from theoverall stock of bottle crates. A special issue relates amongst othersto product series which may display fundamental defects: thus with oneseries the UV-stablilisation of the plastic may be insufficient, withanother series the manufacturing and starting material may be bad, withstill another series the pigmentation is not satisfactory, or withanother series certain production data were selected incorrectly etc.Generally such defects are not ascertained immediately, but becomenoticeable only after the item displaying such inherent defects has beenin use for some time, ie. they can only be detected by the usual means,which mostly are visual checks. The diagrammatic representation in FIG.1 shows a stock of bottle crates F of any size with the number of itemssplit into the groups marked Fxx1, Fxx2 . . . Fyz1 . . . Fzz1, Fzz2.From the circulation flow Z the returned bottle crates go into thestock, which here is shown as a buffer or reservoir. The items of thedifferently marked groups are completely mixed up and when required mustagain be combined into the original groups. This is ensured by a checkpoint KS1, which arranged at a suitable point sorts out, for example,the items of a group Fxx1 which display a manufacturing defect. Suitablepoints are, for example, internal circulations as occur during thefilling, cleaning etc. The items which do not belong to a sorted groupgo back into the recirculation RZ.

The separated group Fxx1 can be dealt with in two ways. If one assumesthat at an approximately identical wear load an entire issue has for thegreater part come to the end of the defined service life, the stillusable crates of a group Rxx1 can, for example, be sorted out by handor, if in view of the small quantity this is not worth it, the entire"issue" can be eliminated. The assessment whether a bottle crate canstill be used and for how long it can still be used in this state, canprobably only be entrusted to a person with the right experience. Thisis where a further characteristic of the invention comes to the fore,this time with regard to the device for performing the method; if abottle crate is still found suitable, it should be possible to allocateit to another, ie. more recent group.

As mentioned in the foregoing, the sorted group Fxx1, if not thrown outat the first check point, can at a second check point KS2 be split intostill usable items of a group Rxx1 and into unsuitable, to be eliminateditems of a group Axx1. As already mentioned, the criterion of a secondcheck is an economic criterion, seeing that this checking operation hasto be carried out by people.

The fastest and possibly also the most economical manner would be thesorting out of a group, the items of which are for the greater partrated as having become unsuitable, in which connection the"unsuitability" is indicated by a statistical distribution. If thisdistribution is relatively wide, then it will be worthwhile to re-checkthe group, returning the still suitable items to more recent groups, eg.Rxx1 to Fxx2. In this connection it must be possible to change themarking that identifies the group.

FIG. 2 now shows an embodiment of the device according to the inventionfor performing the method described in the foregoing. On a bottle crate1, of which only part is illustrated, one notes a marking which consistsof a series of holes 2a, 2b . . . 2k positioned above one another. Everyhole corresponds to a certain height and an issue related thereto. Themarking is arranged, for example, on the narrow sides of the bottlecrates so that it can be read properly, irrespective of the workingposition. On the belt conveyor two positions are possible so that thesame marking is provided once again diagonally offset on the secondnarrow side of the bottle crate. The marking forms an integral part ofthe crate, and when producing the crate it is provided thereon, eg. bymeans of an injection moulding operation. In this manner the year ofmanufacture of a crate can easily be detected optically by means of asimple, height-adjustable photocell device, and the crate can be sortedout accordingly. If a bottle crate is to be allocated to a more recentyear of manufacture, it is given one more hole if provision is made thatthe number of holes increases with the years of manufacture.

FIG. 3 shows a second considerably different embodiment of the deviceaccording to the invention, which also comprises an optically readablemarking 4 stamped into the bottle crate or into the material 5 thereof,which marking 4 consists of a plurality of web-like raised parts 6, 6',etc. Each individual web of the length L is divided into 3 sections ofthe same size o, m and p, so that a single marking bar is able toindicate six conditions seeing that the web height H can be stepped downin thirds. In this way two webs can indicate 36 conditions and n webs 6to the power of n conditions. Sufficient possibilities to store, inaddition to the age of the bottle crate, also other information, eg. thematerial, pigment, origin and other fine-grain data. Since it ispossible to take down the web purely materially, the codings can fororganisation purposes be provided in such a way that, for example, by agrinding down or solely by an optical changing of a web part o, m, p,re-dating can be achieved. For bottle crates which are to be sorted out,the additional information serves as an organisational means for there-acquisition. Because of this coding it now is possible to removedefective series as described above, eg. 2000 pieces, also from of astock which comprises millions of items, and to eliminate them withoutthe need of, basically from a statistical point of view, less effectivebut nevertheless complicated and expensive visual checks by people. Howimportant it may be to remove certain defective issues from the stock,has already been indicated at the outset.

The reading of the marking integrated in the bottle crate material takesplace by optical means, which either are already available or are alsoeasily obtainable on the market. The embodiment discussed here isextremely suitable for a computerised detection and control. A normaldimensioning of the marking is, for example, as follows:

Length of a marking bar: L=20 mm

Height of the stamping: H=1 mm

Width of a marking bar: B=1.5 mm

Distance between marking bars: A=2.5 mm

The following is an example for the organisation of the marking bars onthe bottle crate and the data related thereto:

Group A: injection mould number and crate type bars 1+2+3

Group B: year or date of manufacture bars 4+5

Group C: raw material and guarantee data bars 6+7

Group D: ownership details of the crate bars 8+9

Group E: production/manufacturer a.o. bar 10

Such groupings are, of course, optional and can be chosen and arrangedat will in accordance with the requirements. It also is not necessary toselect 10 marking webs 6; in view of the relatively high data density,fewer webs will generally suffice. However, when computers are used, itis advantageous that the maximum data density is not fully utilised,seeing that the re-dating becomes increasingly difficult, the greaterthe utilisation.

FIG. 4 shows a section of all that can be obtained with only threemarking webs. By way of example these codes are allocated to the groupA, which furnishes information on the injection mould and the cratetype. If a redating is necessary, the codes of this group are notinvolved, but only the codes of group B, which furnishes information onthe date of manufacture. In the case of a re-dating a third part of theweb o, m, p is taken down, which in the illustration of FIG. 4 wouldthen correspond to the white parts of the bars.

As intended by the invention, the marking 3 of the first embodiment andthe marking 4 of the second embodiment form an integral part of thebottle crate, ie. it is incorporated in the material thereof so that itcannot get lost. With the first embodiment the marking consists ofsimple holes, which can also still be produced at a later date, andwhich need not necessarily be round, ie. in the form of drill-holes.Advantageously, however, every "year of manufacture"--with these meansit is after all only possible to indicate the year--is stamped in duringthe manufacture, and an additional perforation is used only for there-dating. In this manner the desired economy is ensured. With thesecond, far more differentiated embodiment, the multibar-marking must atany rate be produced during the manufacture of the bottle crate. To thisend the mould is provided with a simple stamping insert with thenecessary information, the depth H of the stamping being provided insuch a way that at least with regard to time it is forward-compatible bya taking down of web sections.

Summarising once again, the invention consists of a method for sortingout certain containers, eg. bottle crates, industrial containers, from astock of containers by means of optical detection, characterised in thatthe containers of a common issue are given a specific marking so thatthey can be recognised as belonging together, in that after being mixedup during use the containers of a common issue are again broughttogether, and in that the items of a common issue that have been broughttogether are eliminated from the overall stock. Furthermore, in that themarking is detected optically and the decision mechanism is controlledwith the gathered information, so that the items of a sub-quantityrecognised as belonging together are sorted out from an overallquantity, and in that the sorted quantity is checked during a furtherstage of the process so as to detect containers that can be used again,and these are re-allocated to a more reccent issue.

Furthermore, before returning items of a sorted-out sub-quantity to theoverall quantity, the marking can be changed.

The invention also consists of a device on a container for theidentification of a container to be sorted out in order to perform themethod described above, and is characterised in that every containerbears a marking (3, 4) of the own characteristics, and this markingcontains information of the containers; the information stored in themarking contains data on the manufacture and/or manufacturer of thecontainer, the marking (3, 4) being stamped into the material of thecontainer as an integral part of the container during the manufacturethereof, and the marking can be changed with regard to the information.

The device is furthermore characterised in that the integrated marking(3, 4) can be changed from a marking (3) indicating an older date ofmanufacture (2a) to a marking indicating a more recent date ofmanufacture (2b). Also in that the marking consists of a series ofoptically readable perforations in the material of the container (2a).

The marking (4) also consists of a plurality of optically readableweb-like raised parts (6, 6') in the surface of the container and may bea multibar marking (FIG. 4), in which case a marking bar (6, 6')comprises at least two height stages (H) in halves (o, m) or three ormore height stages (H) in thirds (o, m, p), etc.

I claim:
 1. Method for sorting out containers, such as bottle crates andindustrial containers, from a stock of containers by means of opticaldetection, which comprises: providing a stock of containers withspecific markings from which it can be noted if they belong to a commonissue, whereby after being mixed up during use the containers of acommon issue are brought together; optically detecting said markings;separating containers from said stock based on the optical detection ofcontainers belonging to a common issue; further checking the separatedcontainers at a further processing stage for reuseable containers; andreturning said reuseable containers to a more recent common issue,wherein the marking is changed before returning separated items to saidmore recent common issue.
 2. Device for the identification of acontainer, such as bottle crates and industrial containers, to be sortedout from a stock of containers by means of optical detection, whichcomprises a stock of containers with specific optically detectablemarkings from which it can be noted if they belong to a common issuewhereby after being mixed up during use the containers of a common issueare brought together, characterized in that each container bears amarking identifying characteristics of the container wherein saidmarking is stamped into the material of the container as an integralpart thereof during the manufacture thereof and the marking is such thatit can be changed with regard to the information therein from a markingindicating an older date of manufacture to a marking indicating a morerecent date of manufacture.
 3. Device according to claim 2 wherein themarking consists of a series of optically readable perforations in thematerial of the container.
 4. Device according to claim 2 wherein themarking consists of a plurality of optically readable, web-like raisedparts in the surface of the container.
 5. Device according to claim 4wherein the marking is a multibar marking.
 6. Device according to claim5 wherein a marking bar comprises at least two height stages.
 7. Deviceaccording to claim 5 wherein a marking bar comprises at least 3 heightstages.